In National Geographic, astronomer explains growing black hole

The black hole heavyweight of the nearby universe could be an even heftier behemoth than previously believed. Now, using a supercomputer at TheUniversity of Texas at Austin, astronomer Karl Gebhardtand colleagues have re-run the numbers that suggest the supermassive black hole at the heart of the giant galaxy M87 weighs the same as 6.4 billion suns two to three times heavier than previous estimates. The new estimate suggests that a large bulk of the mass initially thought to belong to stars at M87's core is actually locked up in the halo at the galaxy's outer edge.